907
|
| posted on 5/9/09 at 07:26 AM |
|
|
There are heat treatable aluminium alloys and precipitation hardening (age hardening) aluminium based alloys,
aircraft are made from them, but as far as I know normal (pure) aluminium is not heat treatable,
well only to soften it. (annealing)
Cheers
Paul G
|
|
|
|
|
Fred W B
|
| posted on 6/9/09 at 04:06 PM |
|
|
The OP said
quote:
im using 3 1/2" tube 3mm thick wall
Doesn't sound like a space frame to me?
Fred W B
You can do it quickly. You can do it cheap. You can do it right. – Pick any two.
|
|
|
vinnievector
|
| posted on 6/9/09 at 04:24 PM |
|
|
your
unless you have shed loads of cash salt baths and temper treatment ovens forget it buy the best quality steel nice welder nice mitre saw and get busy
forget the ally root you cant really use welding this will just snap around the weld .so you have to go the nut bolt root your working in tubing too
all those fittings you will have to make up.
|
|
|
Theshed
|
| posted on 6/9/09 at 07:32 PM |
|
|
Lots of negativity here! Can I mention the Lotus Elise? Extrusions bonded and then (apparently only for PR) screwed with self tappers?? Welding is
only one way of joining metal. Aircraft do not (often) fall out of the sky and they use rivets - as did most formula 1 cars of the 70's.
I have a welding book somewhere where the author uses a tig welded cobra chassis as an example. RCR make a very nice Lola T70 from welded
aluminium.
Most motorbikes do not exclusively use castings they use castings welded to extrusions.
Having said all that.....steel is obviously easier and from an engineering point of view better! On the other hand if some other nutter wishes to join
me and build a car from aluminium - why not! (errm time money and mainly ....lonelyness!)
|
|
|
iank
|
| posted on 6/9/09 at 07:51 PM |
|
|
quote:
Originally posted by Theshed
Lots of negativity here! Can I mention the Lotus Elise? Extrusions bonded and then (apparently only for PR) screwed with self tappers?? Welding is
only one way of joining metal. Aircraft do not (often) fall out of the sky and they use rivets - as did most formula 1 cars of the 70's.
I have a welding book somewhere where the author uses a tig welded cobra chassis as an example. RCR make a very nice Lola T70 from welded
aluminium.
Most motorbikes do not exclusively use castings they use castings welded to extrusions.
Having said all that.....steel is obviously easier and from an engineering point of view better! On the other hand if some other nutter wishes to join
me and build a car from aluminium - why not! (errm time money and mainly ....lonelyness!)
The negativity is purely against using aluminium for a spaceframe - a design of chassis design for which it is singularly unsuited - that's one
of the reasons why none of the cars/aircraft you mention use one (that and the attitude of the OP to any criticism).
If it was aluminium being proposed for a properly designed glued/riveted monocoque or an elise style chassis their would be more positive comments and
just worries about how to prove it was structurally safe to the IVA men (lots of complex calcs and material science required from a proper engineer in
all likelihood) and comments about the cost/benefit of that construction.
I personally don't believe, from what I've read from people with a lot more experience of the material and it's properties, that you
could ever pass the IVA test with a welded aluminium chassis, especially a spaceframe.
[Edited on 7/9/09 by iank]
--
Never argue with an idiot. They drag you down to their level, then beat you with experience.
Anonymous
|
|
|
kb58
|
| posted on 7/9/09 at 03:18 AM |
|
|
quote:
Originally posted by Theshed
Lots of negativity here!
It is wrong to assume negative = wrong.
Mid-engine Locost - http://www.midlana.com
And the book - http://www.lulu.com/shop/kurt-bilinski/midlana/paperback/product-21330662.html
Kimini - a tube-frame, carbon shell, Honda Prelude VTEC mid-engine Mini: http://www.kimini.com
And its book -
http://www.lulu.com/shop/kurt-bilinski/kimini-how-to-design-and-build-a-mid-engine-sports-car-from-scratch/paperback/product-4858803.html
|
|
|
Theshed
|
| posted on 7/9/09 at 11:26 AM |
|
|
"It is wrong to assume negative = wrong"
I didn't! I was trying to say that whilst I would be the first to say that an aluminium chassis is many many times harder to build and has very
few, if any, advantages over a steel spaceframe it is not an impossible task.
Very obviously starting with a pile of 25mm square ali tubing and welding up a locost style chassis would be very silly. However there are many
examples of welded aluminium cars out there on the net. Probably fair to say that the term "spaceframe" is stretched a bit. I would
describe the lotus as a spaceframe. Another example is the Shelby Mk1.
I did not read the initial poster's "other thread" so please do not take any of this as a defence of any attempt to fabricate an
aluminium frame by copying processes that work in steel. In that respect negativity is richly deserved. On the other hand out of the box thinking is
surely to be encouraged?
|
|
|
Theshed
|
| posted on 7/9/09 at 11:33 AM |
|
|
I have just read the other thread...........Now I understand!
|
|
|
TheGecko
|
| posted on 7/9/09 at 12:26 PM |
|
|
quote:
Originally posted by Theshed
Probably fair to say that the term "spaceframe" is stretched a bit. I would describe the lotus as a spaceframe.
I would think that
calling the Elise chassis a "space frame" is drawing a very long bow indeed. It's probably best described as a "twin
tube" because there are only the two primary longitudinal members which are of very deep section.
Dominic
[Edited on 7/9/2009 by TheGecko]
|
|
|
scootz
|
| posted on 7/9/09 at 09:01 PM |
|
|
quote:
Originally posted by Theshed
I would describe the lotus as a spaceframe.
Sorry, but I completely and utterly disagree with that - 'spaceframe' is just about the last word I would use to describe the Elise
variant chassis.
|
|
|
Mark Allanson
|
| posted on 7/9/09 at 09:25 PM |
|
|
..or Audi's description of the A2 chassis
If you can keep you head, whilst all others around you are losing theirs, you are not fully aware of the situation
|
|
|
FEZ1025
|
| posted on 7/9/09 at 10:46 PM |
|
|
Please don't feed the troll, this isn't the only forum he uses as a lunch table.
Alan...
|
|
|
flak monkey
|
| posted on 8/9/09 at 06:15 AM |
|
|
Possibly the most comprehensive discussion on the matter:
http://locostbuilders.co.uk/viewthread.php?tid=79918
Long and short of it is the chassis needs to be designed for the material you are making it out of. A spaceframe by its very design doesnt lend itself
to aluminium construction. Other types of chassis (monocoque, twin beam etc) all do, but require a considerable level of knowledge and expertise to
get right.
Sera
http://www.motosera.com
|
|
|
philipcurtis100
|
| posted on 8/9/09 at 04:54 PM |
|
|
thanks
|
|
|
